1. Field of the Invention
The invention relates to a switch, and more particularly to an optical switch that can be shifted to different operating modes using a slide disc.
2. Description of the Related Art
Referring to FIG. 1, a conventional position-sensing device for a digital camera, as disclosed in Taiwanese Patent Publication No. 568480, includes an optical module 11 and a control module 12. The optical module 11 has a light source 111, and two light-receiving devices 112, 113 disposed respectively on two opposite sides of the light source 111. The control module 12 has a main body 121, a receiving chamber 122 formed in the main body 121, and a reflective ball body 123 disposed rollably in the receiving chamber 122. When the light source 111 emits light, the light can be reflected to the light-receiving device 112 or 113 through the reflective ball body 123. According to the condition of light received by the light-receiving device 112 or 113, the position of the digital camera can be detected.
However, since an outer surface of the reflective ball body 123 is curved, the light will diverge along the curved surface of the reflective ball body 123, so that the position of the reflective ball body 123 and the angle of light after reflection cannot be easily controlled. Hence, the light-receiving devices 112 and 113 that are disposed on the same side as the light source 111 may not easily sense the light rays.
Referring to FIG. 2, another conventional position-sensing device similarly includes an optical module 13 and a control module 14. The optical module 13 has a light source 131, and two light-receiving devices 132, 133 that are coplanar but not collinear with the light source 131. A reflective plate (not shown) faces the optical module 13. The control module 14 has a main body 142 disposed between the optical module 13 and the reflective plate, a receiving chamber 143 formed in the main body 142, and a ball body 144 disposed rollably in the receiving chamber 143. When the light source 131 emits light, the light can be reflected to the light-receiving device 132 or 133 through the reflective plate. According to the condition of light received by the light-receiving device 112 or 113, the position of the digital camera can be detected. Similarly, since an outer surface of the ball body 144 is curved, the position of the ball body 144 and the angle of light after reflection cannot be easily controlled.